Opti Forecast 7/20

Sailing Weather Forecast

Optimist Nationals

Lake Minnetonka, MN

Issued: 0700LT Friday, 20 JULY 2007

 

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WEATHER RISKS: There are no active weather warnings or advisories for the sailing area.

Please tune your VHF to NOAA Weather Radio for the latest official warnings and advisories.

 

Synopsis: The forecast generally remained on track yesterday with a northerly breeze at 4-8 kts to begin and conclude the sailing day. During the midday hours the predicted build in wind speed to 10-15 kts and slight shift to the NNE occurred.   

 

Today, high pressure settling southward from Canada dominates the weather picture across the upper Midwest. The high produces bright blue skies across the Lake Minnetonka area and a light ESE-SE wind. The high will stick around for several days so the sunshine continues through the weekend with building heat each day.  

 

Current Conditions: Surface observations including the MYC weather station are indicating a light E to ESE breeze at 2-5 kts with gusts to 7 kts over Lake Minnetonka at 0630 this morning.    

 

A few scattered clouds are depicted across southern Minnesota on satellite images this morning. Visibility is unrestricted at 10 mi or greater in the cool dry air.  

 

Forecast Discussion: Winds should turn SE by 0900 and remain that way at 3-6 kts through 1100. A very slight left hand shift to the ESE is then expected as a small build in wind speed to 5-8 kts with gusts to 11 kts occurs. Near 1500 the wind relaxes back to 3-6 kts and again turns SE.     

 

Weather: Sunny skies can be expected to shine through the day. Low humidity means comfortable conditions with a high temperature near 79 F. Sunscreen should be worn with a high UV index of 9.

 

Seas: The lake surface should remain calm today in the light air. The best shot at some very slight chop occurs around midday with the small bump-up in wind speed. 

 

Detailed Wind Forecast for Today (07/20/2007):

Time(LT)  Wind Speed    Wind Direction 

1000      03-06         SE   

1100      04-07         ESE-SE      …slight build in speed underway

1200      04-08         ESE         …small left hand shift.

1300      05-08         ESE

1400      05-08         ESE        

1500      04-07         ESE-SE      …easing wind speeds, slight right shift

1600      04-07         SE   

1700      03-06         SE          …declining/shiftier winds late day

1800      03-06         SE

 

Hedge: Forecast confidence is ABOVE AVERAGE for wind speed and AVERAGE for wind direction. A breeze from the indicated ESE and SE directions should occur through the day. However, in this light air the wind can become shifty and occasionally break from the forecasted directions to the E or S. The best way to avoid this is to stay away from the eastern and southern shores of the lake where extremely light and shifty wind is likely. The steadiest wind will occur over the center of the lake and towards the northern and western shore.    

 

Saturday (21 JULY 2007): The day begins with a 4-6 kt wind out of the SSE. Late in the morning, near 1100, a right shift to the S occurs as the wind builds to 7-11 kts with gusts to 16 kts. The wind remains southerly through the afternoon but eases to 5-9 kts late in the day.

 

Detailed Wind Forecast for Saturday (07/21/2007):

Time(LT)  Wind Speed    Wind Direction

1000      04-06         SSE

1200      07-11         SSE-S

1400      07-11         S

1600      06-10         S

1800      05-09         S

 

Weather: The weather story tomorrow is again focused on high pressure as is extends from Minnesota through the Great Lakes. Sunny skies are in the works though a few clouds may pop up during the afternoon. It will be a bit muggier as the humidity builds and temperatures reach 85 F.  

 

LONG RANGE OUTLOOK

 

Sunday (22 JULY 2007): Winds remain southerly through the day and increase from 4-7 kts in the morning to 6-10 kts in the afternoon. Sunshine with occasional afternoon clouds, a high of 90 F.

 

Monday (23 JULY 2007): A SSW wind in the morning at 3-6 kts becomes SW and builds to 5-10 kts by midday and though the afternoon. Sunshine with a few afternoon clouds, 92 F for a high.   

 

Tuesday (24 JULY 2007): Expect a persistent SW flow building from 2-4 kts early to 4-7 kts midday. A high near 91 under mostly sunny skies.